Retaining walls used to retain soil and the like must have drainage aggregate, and a perforated drain pipe that leads to daylight for the sole purpose of draining water out from behind the wall. Water that is not drained from behind retaining walls can cause mass slope failure, and heaving of the wall if it were to freeze.
In architectural walls and other similar types of retaining walls which are made from a plurality of stackable block-like elements, drainage holes are often provided in the wall to facilitate the evacuation of water from the soil behind the wall. Commonly, such holes are provided with drainage pipes that further facilitate the evacuation of water. In the above-described installations, the hole is typically cut in a square shape while the pipe is round, leaving unsightly empty spaces or void areas between the pipe and the surrounding wall. These spaces or void areas often collect garbage and other debris, and rodents tend to nest in the drainage holes, making these drain pipes even more of an eyesore, as well as a nuisance.